Modular Fluid Storage Tank

ABSTRACT

A modular fluid storage tank is formed by a plurality of curved support footings, a tank bottom circular sheet and a plurality of curved wall panel sections. Each footing includes a channel extending on its top surface. The footings are positioned in a circular pattern and the tank bottom sheet is positioned to extend over the channel. The wall panel sections have a bottom portion configured to fit within the footing channels. Suitable tie down clamps are provided to secure the wall panel sections to the footings. Adjacent sides of the wall panel sections are secured to each other to complete the assembly.

This application is related to application Ser. No. 13/584,882 filed on Aug. 14, 2012.

BACKGROUND OF INVENTION

1. Field of the Invention

This application relates to a fluid storage tank that can be assembled at a remote location where a supply of fluid, for example water, is needed.

An example of such a situation occurs where an oil or gas well treatment process such as fracturing is conducted at the well site. In such a situation either a large temporary water storage tank is assembled on site or a plurality of smaller portable water tanks are delivered to the site.

2. Description of Related Art

In the oil and gas industry, water storage has become an issue due to the large amount of barrels of water required to perform drilling operations. Cost of transporting a large number of tanks to location, and logistical problems of having enough space at the well site to accommodate their positioning has forced the oil and gas industry to find a solution. The solution that has developed is the use of a single mobile erecting tank. These tanks eliminate a large fleet of storage vessels and the cost of transporting them to location.

These large capacity tanks normally comprise 16 single panels that connect together side by side, forming in one embodiment a 122 ft. diameter tank with a height of 12 ft. After they are assembled a rubber sheet, plastic, or polypropylene sheet is positioned in the inside and the edges are laid over the top rail of the tank. These edges of the sheet are secured to the top rail by the use of c-clamps.

The suction lines are then hung over into the tank and the tank is then filled with water. As the tank is filled, water forces the sheet into the lower inside corners of the tank. This can allow the sheet to be pinched or protrude under the wall of the tank causing a leak or tear of the rubber sheet.

A drain sump is formed under the sheet so that most of the water can be evacuated from the tank.

An improved modular storage tank is disclosed in copending application Ser. No. 13/584,883 filed Aug. 14, 2012. However, the sheet that forms the bottom of the tank needs to extend up and over the sides of the tank which requires more material. Also it is still necessary to construct a sump in the ground to facilitate emptying of the tank.

BRIEF SUMMARY OF THE INVENTION

A fluid storage tank is formed by a plurality of arcuate wall support footings that provide structural support for a plurality of wall panel sections and also hold the floor sheet of the tank in sealing engagement with the wall panels without the need for the sheet to extend upwardly over the top of the wall panels. The footings also form a sump so that the water may be entirely withdrawn from the tank without the need for forming a sump ditch.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a perspective view of a fluid tank according to an embodiment of the invention.

FIG. 2 is a top view of a support footing according to an embodiment of the invention.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2.

FIG. 4 is a cross-sectional view of a support fitting showing a wall portion fixed within the support footing.

FIG. 5 is a cross-sectional view of the vertical joint between adjacent wall sections.

FIG. 6 is an exploded view of the vertical wall joint between adjacent wall panels.

FIG. 7 is a cross-sectional view of a second embodiment of a support footing according to an embodiment of the invention.

FIG. 8 is a front view of a second embodiment of coupling structure for two adjacent panels according to the invention.

FIG. 9 is a top view of the coupling shown in FIG. 8.

FIG. 10 is a side view of a panel.

FIG. 11 is a perspective view of a coupling pin.

FIG. 12 is a top view of the support footing shown in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, an embodiment of the instant invention is a storage tank 10 formed from a plurality of individual curved wall panel sections 9 connected to each other at 8. Wall panel sections 9 are supported by a plurality of footings 13 shown in greater detail in FIGS. 2 and 3. Wall panel sections 9 are placed on footings 13 in such a manner that wall joints 8 are located at approximately the mid-point of each footing 13.

As shown in FIGS. 2 and 3, each footing includes a bottom curved plate member 18, an angled plate 19, a top plate 11 and an end wall plate 26. Suitable supports 27 and 28 extend from top plate 11 and angled plate 9 to lower plate member 18 all of which are curved. Lower plate member 18 rests on the ground when the tank is constructed. A pair of curved rails 24 and 25 extends along the top plate 11 and are secured thereto by a suitable means such as by welding. Rails 24 and 25 may be solid or hollow, and may be square or rectangular in cross section for example. A channel 4 is formed between rails 24 and 25. A plurality of apertures 22 are formed in top plate 11 and a plurality of nuts 29 are fixed to the underside of top plate 11 in alignment with the apertures. A foundation for the tank is formed by positioning a plurality of the footings 13 in a circular array on the ground as shown in FIG. 1

Once the footings are arranged in a circular pattern, a circular floor sheet 42 having a diameter slightly larger than that of the tank is laid over the footings in the manner shown in FIG. 4. A pair of rubber gaskets 43 and 44 may be positioned underneath floor sheet 42 and over floor sheet 42 as shown in FIG. 4 to provide a water tight seal. Flexible sheet 42 may be made of rubber, for example.

After sheet 42 and gaskets 43 and 44 have been laid over rails 24 and 25, wall panels 9 are placed on footings 13. As shown in FIG. 4, wall panel sections 9 include a lower frame member 41 having a rectangular cross section and an upstanding wall portion 35. Frame member 41 is curved to the same extent that rails 25 and 26 are curved. Thus frame member 41 will fit in channel 4 between rails 24 and 25. The weight of wall panels 9 will slightly deform rubber gaskets 43 and 44 and bottom sheet 42 so as to form a tight seal. The channel 4 formed by rails 24 and 25 and top plate 11 provide lateral support for wall panel section 9. To provide further stability, a plurality of tie down clamps 37 are located on the support footings. Tie down clamps 37 include by way of example an L-shaped member having a first portion 36 that overlies bottom frame member 41 of the wall panel section and a second leg portion 39 that engages the top surface of the footing. The tie down clamp includes an aperture 38. A threaded bolt 31 extends through aperture 38 and aperture 22 in the footing. The threads on the bolt 31 engage threaded nut 32 so that the tie down clamps are secured to the footings and thus further hold wall panel section 9 in place.

As shown in FIG. 4, sloping wall portion 19 of the footing creates a natural sump area for facilitating complete draining of the tank. The clamps may include one or more strengthening flanges 34.

FIGS. 5 and 6 illustrates an embodiment of the joint structure between adjoining wall panels. A first wall panel 63 includes a metal strip 59 attached to the panel by a plurality of vertically spaced bolts and nuts 51 and 52. Metal strip includes a V-shaped portion 70. A second metal strip 60 is attached to wall panel 62 by a plurality of bolts 71 and nuts 72. Metal strip 60 has an angled portion 73 that abuts against V-portion 70 as shown in FIG. 5. A plurality of tabs 55 with an opening 56 extend outwardly from V-shaped portion 70 through slots 75 formed in section 73 of strip 60.

A reinforcement plate 58 having openings therein and rubber gasket 76 extend along both sides of joints 8 and are attached at either side to adjacent wall panels 62 and 63 as shown in FIG. 6. Pins 80 may be placed through holes 56 in tabs 55 thereby further securing the wall panels together. Additionally a rectangular reinforcing plate 57 can be fixed to angled portion 73 about each tab 55.

A second embodiment of a support footing 110 according to the invention is illustrated in FIG. 7. Each footing 110 includes a curved base plate 111 which may be about 24 inches wide. A plurality of footing 110 for example 16 are placed in a circle to form a support for the wall panels 9 shown in FIG. 1. A pair of curved rails 125 and 126 are fixedly secured to base plate 111 such as by welding. Rails 126 and 125 may be solid or hollow tubulars, and may be rectangular in cross section. As shown in FIG. 12, rails 126 and 125 are spaced apart so as to form a rectangularly shaped channel 199 sized to receive a lower frame member 141 of panel 9. Lower frame member 141 of panel 135 may have a rectangular cross section that fits within rectangularly shaped channel 199. The support footing 110 also includes a plurality of L-shaped brackets 137 that include a horizontal section 136 and a vertical section 139. Vertical section rests on base plate 111 and horizontal portion 137 extends over lower frame member 141 of panel 135 as shown in FIG. 7. As in the embodiments of FIG. 1, a flexible tank floor sheet 142 and optionally a pair of rubber gaskets 144 and 145 over and below sheet 142 are first placed over rail members 125 and 126. Wall panels 9 are then placed on the support footings so that lower frame member 141 is positioned within channel 199. The weight of wall panels 9 will compress flooring sheet 142 and gaskets 144 and 145 to form a fluid tight seal, thus eliminating the need for the flexible floor sheet 142 to extend over the top of the wall panels.

Clamps 137 may then be installed to further secure the wall panels to the footings by means of threaded bolts 131 that extend through openings 138 in horizontal portion 136 and are threaded into threaded holes 140 provided in base plate 111.

FIGS. 8-11 illustrate a second embodiment of a coupling arrangement for adjacent wall panels according to the invention. FIG. 8 shows adjacent wall panels 9 and 7. A first wall panel 9 has a top frame member 121, a bottom frame member 124 and a side frame member 130 extending from top frame 121 to bottom frame member 124. All three frame members may be rectangular tubing. The same is true for adjacent wall panel 7 which is constructed in the same manner as wall panel 9. A first reinforcing plate 128 extends from bottom frame member 124 to top member 121 and one end of the wall panel. A second reinforcing plate 129 extends between bottom frame member 124 to top frame member 121 at a second end of the wall panel. Reinforcing plates 128 and 129 are fabricated from relatively stiff material such as steel. The plates include a plurality of apertures 126 and 127. As disclosed in copending application Ser. No. 13/584,882, filed on Aug. 14, 2012, the entire contents of which is hereby expressly incorporated herein by reference thereto, wall panels 9 and 8 may include a plurality of flexible reinforcing bands 123 which are connected at their ends to steel plates 128 and 129.

The coupling arrangement also includes a connector plate 152, which may be slightly curved to conform to the curvature of wall panels 9 and 7 which extends along and overlaps the ends of adjacent wall panels as shown in FIG. 9. Connector plate 152 has a plurality of apertures which align with apertures 126 and 127. Suitable bolts 141 and 143 are adapted to pass through the apertures in connector plate 152 and apertures 126 and 127 in reinforcing plates 128 and 129. Fasteners such as nuts can then be used to secure the connector plate 152 and reinforcing plates together or apertures 126 and 127 may be threaded. A strip 153 of gasket type material may be placed between connector plate 152 and reinforcing plates 128 and 129.

The holes in connector plate 152 and those in reinforcing plates 128 and 129 are aligned such that a gap 151 of approximately one half inch is maintained between adjacent panels 9 and 7.

The coupling assembly may further include a plurality of U-shaped members 170 fixedly secured such as by welding to the front vertically extending surfaces of side frame member 130 and 131. A plurality of locking pins 162 have a generally cylindrical core member 164. Four radially extending circular flanges 163 extending outwardly from core member 164 and form recesses 165 and 166 at either end of the locking pins. These recesses are sized to fit within the U-shaped channels of members 170 as shown in FIG. 9. This arrangement further presents lateral separation of the wall panels.

Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims. 

I claim:
 1. A modular fluid storage tank comprising: a plurality of arcuate footing having a channel extending along their length and arranged in a circle; a circular bottom sheet covering a circular space formed by the footings, the bottom sheet extending over the channels in the footings; a plurality of wall panel sections having a bottom portion, the bottom portion of each wall panel section being configured to fit within the footing channels with the bottom sheet positioned between a bottom portion of each wall panel section and the footing channel; and means for securing adjacent wall panel sections to each other along a vertical joint.
 2. A modular fluid storage tank according to claim 1 further including a plurality of tie down clamps securing each wall panel section to the footings.
 3. A modular fluid storage tank according to claim 2 wherein the wall panel sections have a lower frame member positioned within the channels and the tie down clamps have a first member overlying the lower frame member and a second member secured to the footings.
 4. A modular fluid storage tank according to claim 1 wherein the channel is formed by a pair of a parallel curved rails attached to an upper surface of the footing.
 5. A modular fluid storage tank as claimed in claim 1 wherein each footing includes an upper plate having a plurality of openings therein, and a plurality of nuts secured to an underside portion of the upper plate in registry with the openings.
 6. A modular fluid storage tank as claimed in claim 1 wherein each footing includes a top plate, a bottom plate and an angled plate extending between the top plate and the bottom plate, and wherein the bottom plate has a width greater than the width of the top plate.
 7. A modular fluid storage tank as claimed in claim 6 wherein the angled plate extends inwardly from the top plate down to the bottom plate.
 8. A modular fluid storage tank as claimed in claim 1 further including a gasket positioned between the wall panel section and the bottom sheet.
 9. A modular fluid storage tank as claimed in claim 8 including a second gasket positioned between the bottom sheet and the footing.
 10. A modular fluid storage tank as claimed in claim 6 further including a plurality of reinforcing supports extending between the top and bottom plates of the footings.
 11. A modular fluid storage tank as claimed in claim 1 wherein the wall panel sections have a top portion, a bottom portion and two vertically extending side wall portions, wherein the vertically extending side wall portions of each wall panel sections are secured to each other by a joint.
 12. A modular fluid storage tank according to claim 11 wherein each joint comprises a first vertically extending strip having a v-shaped portion attached to one wall panel section and a second vertically extending strip attached to an adjacent wall panel section, the second strip having an angled portion overlying a portion of the v-shaped portion of the first strip.
 13. A modular fluid storage tank according to claim 12 wherein the first strip has a plurality of tabs and the second strip has a plurality of slots through which the tabs extend.
 14. A modular fluid storage tank according to claim 13 wherein each joint further includes a reinforcement plate and a gasket extending vertically along the sides of adjacent wall panel sections along the inside surface of the wall panel sections and attached to each adjacent wall panel sections.
 15. A footing for a modular fluid storage tank comprising: a horizontally curved body having a top surface having width; a channel formed on the top surface.
 16. A footing as claimed in claim 15 wherein the channel is formed by a pair of curved, parallel rails.
 17. A footing as claimed in claim 15 wherein the top surface is formed by a plate having a plurality of holes, and a plurality of nuts secured to an underside of the plate in alignment with the holes.
 18. A footing as claimed in claim 15 wherein the curved body has a bottom surface having a width greater than that of the top surface; and a sloping surface extending inwardly with respect to a center of curvature from the top surface to the bottom surface.
 19. A footing as claimed in claim 17 further including a plurality of tie down clamps and a plurality of threaded bolts extending through an aperture in the tie down clamp and the holes and nuts located on the top surface of the footing.
 20. A footing as claimed in claim 15 further including a plurality of tie down clamps having a first vertical portion in contact with the curved body and a second horizontal portion adapted to rest on top of a lower frame member of a wall panel, and means for securing the clamps to the curved body.
 21. A modular fluid storage tank as claimed in claim 11 wherein the joint comprises a first vertically extending plate on one wall panel and a second vertically extending plate on a second adjacent wall panel, and a connector plate attached to the vertically extending first and second plates.
 22. A modular fluid storage tank as claimed in claim 21 further including a plurality of U-shaped members fixed to adjacent panels and a plurality of locking pins positioned within the U-shaped members.
 23. A modular fluid storage tank as claimed in claim 22 wherein the locking pins comprise a generally cylindrical core member and a plurality of radially extending circular flanges. 